Methanogenic Biodegradation of Polycyclic Aromatic Hydrocarbons in Oil Sand Tailing Ponds (OSTP)
Management of oil sands tailings is a component of the broader concept of land reclamation after surface mining. Bitumen extraction from oil sands ore using hot water generates huge volumes of fluid fine tailings that are deposited in oil sands tailings ponds pending reclamation. Methane emissions from tailings and end-pit lakes occur as a result of microbial metabolism of entrained hydrocarbons in tailings deposited in tailing ponds or reclaimed in end pit lakes. Methanogenesis also restrain the progression of end pit lakes into natural aquatic ecosystem, therefore it is important to predict the intensity and longevity of methane emissions from tailings ponds and end pit lakes. Our kinetic model predicts methane production taking into account the microbial metabolism of labile hydrocarbons such as alkanes and monoaromatics. Polycyclic aromatic hydrocarbons (PAHs) had been reported to be found in tailings but few research has been done to assess their biodegradability under methanogenic conditions. Therefore, we investigate the biodegradation of the most abundant PAHs in tailing ponds by indigenous microbial communities under methanogenic conditions. Our preliminary experiments have shown that Naphthalene, Phenanthrene and Pyrene were biodegradable under methanogenic conditions. In the current experiment, tailings collected from Syncrude tailing ponds were amended with Naphthalene, Phenantherene and Pyrene with appropriate baseline and abiotic controls. The experiment is in progress to investigate the PAHs biodegradability under methanogenic conditions, and to model the methane emissions. The results have great application not only for biodegrading recalcitrant hydrocarbons under anaerobic environments but also help improve our existing kinetic model to predict methane production and emissions from tailings ponds and end pit lakes.
Disclaimer: All the contents presented in this website were produced by Henian Guo as an assignment for RENR 580 at the University of Alberta and should NOT be interpreted outside of the scope of this assignment. Parts of the findings were not from the real experiment.